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Camphor is a bad tree factory with a minty smell

Mindy Mohrman, Guest columnist
Published 6:58 p.m. ET Aug. 9, 2018

Camphor tree (Cinnamomum camphora) is able to out-compete stronger, slow-growing native trees in an urban forest due to its fast-growing nature, making it very invasive in Florida.(Photo: . Photo by Forest and Kim Starr, Starr Environmental, Bugwood.org.)

Recent information obtained about our urban forest through an Urban Tree Canopy assessment has quantified Tallahassee’s iconic tree canopy. At 55% tree cover, this is one of the highest tree canopy coverage percentages recorded in the nation.

Community trees offer many benefits, including energy savings, water quality benefits, erosion control, and more, so the dense canopy that shades our streets and homes provides a major benefit to citizens. While this quantity of trees provides great value, the composition of our urban forest – including tree species, condition, and age – can determine the longevity and resilience of our beloved canopy.

Mindy Mohrman(Photo: Mindy Mohrman)

A recent sample inventory of public trees gives us a glimpse into the composition of our urban forest. While our urban forest is relatively diverse, we found that our most common tree species are short lived, weak wooded species with low wind resistance.

This means that a high proportion of our urban forest is made up of species that have low value in an urban environment and are easily damaged by storms. This includes the native species Carolina laurelcherry, water oak, and laurel oak, which make up an estimated 32 percent of our urban forest.

It also includes a Florida Exotic Pest Plant Council Category 1 Invasive Plant, the camphor tree (Cinnamomum camphora).

At an estimated six percent of our urban forest, the camphor tree is our fifth most common tree species. Camphor tree is native to China and Japan, where it is commonly used to produce timber and camphor oil. Camphor tree is an evergreen tree with elliptical leaves that have a shiny, waxy appearance.

Newer leaves are a light bright green, while older ones take on a deep green color. Flowers are borne on panicles about three inches long and are greenish white to pale yellow. The fruit is distinctive, appearing during winter and spring months as small fleshy berries starting green and turning dark blue to black.

Camphor tree is an evergreen with shiny, waxy leaves that smell of menthol when crushed and has distinctive fruit that turns from green to dark blue and black in winter and spring.(Photo: Mindy Mohrman.)

The easiest way to identify camphor is by its smell. A strong menthol odor is released when leaves and twigs are crushed. It is a fast-growing tree which tends to develop poor structure, a dangerous combination that makes it prone to decay and failure of large branches or entire trees in even minor storms.

In Florida, camphor tree is an invasive species, which means it has naturalized and is able to rapidly displace native trees and infest natural areas due to its fast growth habit and ability to produce large amounts of seed. So, this is not just a bad tree due to its tendency towards decay and structural problems. This is a bad tree factory that is constantly reproducing and outcompeting our valuable native trees for space and resources.

Camphor tree is prone to decay and structural problems due to its growth habit, making it prone to failure of large branches or entire trees in even minor Florida storms. Photo by Mindy Mohrman.

Preventing the spread of camphor trees is important for the health and longevity of our urban forest. Controlling the spread is easiest when the trees are young and have not yet begun to develop fruit. Keep a careful eye for the seedling trees and pull them whenever you see them.

Like many invasive species, disturbed areas are particularly vulnerable. A healthy ecosystem with good species diversity will help deter infestation, so strive for a wide array of native plant species in your own yard to support a strong urban forest overall. If you have a large camphor tree on your property, removal and replacement with a high value native species is encouraged!

There are no restrictions on removal of invasive species, however it is always advisable to check with City Growth Management or County Development Support and Environmental Management for species confirmation before scheduling a removal. Staff will inspect the tree to confirm the species and that a permit is not required for its removal.

On single family residential properties, this is required for trees 36 inches in diameter and larger. Consistent attention to the trees sprouting on our own property can go a long way towards building a strong, sustainable, and resilient urban forest. The choices we make today are building the urban forest that future generations of residents will live under.

Mindy Mohrman is the Urban Forester for the Tallahassee-Leon County Planning Department and a volunteer writer for UF/IFAS Extension Leon County. For gardening questions, email the extension office at AskAMasterGardener@ifas.ufl.edu.